Ohlendorf is scheduled to start Tuesday's game against Milwaukee.
In two starts with the Pirates this season, Ohlendorf has no record with a 7.27 earned run average. He last pitched for Pittsburgh on April 8, leaving that start after just 2 2/3 innings because of shoulder discomfort.
The Pirates placed Ohlendorf on the 15-day disabled list the following day and he was eventually transferred to the 60-day DL. He was activated earlier this month and optioned to Indianapolis.
In seven minor league starts this season, the first six on a rehab assignment, Ohlendorf was 1-1 with a 3.65 ERA.
Beimel, signed to a minor league contract in the offseason, appeared in 35 games for the Pirates this season and posted a record of 1-1 with a 5.33 ERA.